Malfunction warning system for pressurized cooling systems

ABSTRACT

A warning system sensitive to loss of pressure as well as undue temperature rise in cooling systems such as in motor vehicle engines. A capsule with a diaphragm-operated electric circuit control senses the pressure loss and this is conveniently connected in the usual temperature-sensing probe circuit to provide a warning, ordinarily a lighted lamp in the driver&#39;&#39;s compartment. The pressure-sensing means is incorporated with the radiator cap or independently mounted on the radiator tank by means of a self-tapping nipple which supports the capsule carrying the pressure-sensing diaphragm.

United States Patent John L. Howard 12802 N. 23rd St., Phoenix, Ariz.85022 [2 I Appl. No. 42,080

[22] Filed June 1, 1970 [45] Patented Nov. 23, I971 [72] Inventor [54]MALFUNCTION WARNING SYSTEM FOR PRESSURIZED COOLING SYSTEMS 6 Claims, 6Drawing Figs.

52 u.s.c| 340/60, 340/240, 200/83 511 int. Cl B60q 1 00, G08b2l/0O 50FieldoiSearch 340/52,52

[5 6] References Cited FOREIGN PATENTS 284,595 4/ l 931 Italy 340/60Primary E.raminer-Alvin H. Waring Attorney-Knox & Knox ABSTRACT: Awarning system sensitive to loss of pressure as well as unduetemperature rise in cooling systems such as in motor vehicle engines. Acapsule with a diaphragm-operated electric circuit control senses thepressure loss and this is conveniently connected in the usualtemperature-sensing probe circuit to provide a warning, ordinarily alighted lamp in the driver's compartment. The pressure-sensing means isincorporated with the radiator cap or independently mounted on theradiator tank by means ofa self-tapping nipple which supports thecapsule carrying the pressure-sensing diaphragm.

PATENTEDuuv 23 lSTl SHEET 1 [IF 2 INVENTOR. JOHN L. HOWARD PATENTEMuv 23|97l 3. 622.976

saw 2 OF 2 INVENTOR. JOHN L. HOWARD Pig's I & jnox MALFUNCTION WARNINGSYSTEM FOR PRESSURIZED COOLING SYSTEMS BACKGROUND OF THE INVENTION Veryfrequently the ordinarily provided temperature gauge on motor vehiclesfails to register significantly any increase in engine temperatureresulting from loss of coolant if the water level in the system is lowand the engine may be damaged by overheating. If the operator dependsentirely upon the temperature gauge a bumed-out engine may result.Whenever an engine is designed for optimal operation at a temperaturewell above 212 F a water or water-based pressurized coolant will tend tobe expelled quickly, at least in part, upon rupture of the integrity ofthe system as when a water hose blows" or the water pump or radiator hasa break therein. On the other hand, even if no great loss of coolant hasoccurred it may be important to signal the fact that a cooling systemdesigned to operate under pressure is not being pressurized, as forexample when a radiator cap has not been properly replaced, the waterpump belt is broken stopping circulation of coolant, or the coolant isfrozen, thus signaling the malfunction before any great damage canoccur.

SUMMARY OF THE INVENTION A pressure sensor reflecting loss of pressurein the water or water-based cooling system of an engine, particularly asapplied to automotive engines. The sensor includes a capsule with adiaphragm exposed to the coolant system and including circuitmake-and-break means connected to a remote electrical warning signalsuch as a red lamp on the instrument board. The capsule is incorporatedwith a radiator cap or is independently attached to the radiator tankand it can be hooked up in parallel with an existing temperature-gauge.

SHORT DESCRIPTION OF THE DRAWINGS showing the pres- DETAILED DESCRIPTIONOF A PREFERRED EMBODIMENT Referring now to the drawings, the principaluse of the invention is represented as application to the cooling systemof automotive vehicle engines, the number indicating fragmentarily anupper inlet portion of a radiator with the usual internal valve seat 12and overflow pipe 14 and the usual complement of radiator cap lockingflanges fragmentarily represented at 16, all of which elements areconventional.

A radiator cap 18 has fixed therein an inner downturned lock plate 20with conventional partial flange structure to engage and lock onto thetop of the radiator inlet 10, and both cap 18 and plate 20 are centrallyapertured to provide a sliding fit for a pressure access tube 22. Theinner edge of the plate 20 is split into fingers 24 terminally turned tominimize friction while assuring good'electrical contact with the tube22. The uppermost portion of the plate 20 defines a circular channel tolocate the upper end of a pressure-regulating helical spring 26 arrangedcoaxially-of the tube 22. The spring 26 is compressed between the plate20 and a valve cup 28 which in turn depresses a washer 30 of a neopreneor the like into sealing relation with the inner valve seat 12 of theradiator inlet.

Supported on the upper end of the pressure access tube 22 is the capsule32 comprised of a lower dished shell 34 fixed as at 36 to the tube 22,an upper, oppositely dished shell 38 with a flexible diaphragm 40peripherally clamped therebetween. The upper shell 38 carries acylindrical casing 42 which conveniently is constructed of plastic andtherefore electrically insulative for. housing a contact plate 44 fixedto the top of a plunger 46. To minimize possibility of damage to thediaphragm the plunger 46 is provided with an enlarged head 48 todistribute the load of the contact spring 50 which is compressed betweenthe contact plate 44 and the rinet-type terminal 52 fixed on a depressedend plate 54 of the casing 42. Depression of the end plate 54 insuresagainst inadvertent electrical contact of the terminal 52 and itslateral extension 56 equipped with a quick disconnect male element.

The plunger is slidingly supported by an axially bored plug 58 fixedwithin an upper neckportion the upper shell 38, this plug beinginsulative, and the upper end 60 of said neck portion of the uppershell, constitutes a lower contact for the contact plate 44 to providean electrical path through the contact spring 50 to the contact plate44, the metal capsule shells and the tube 22, to the lockplate 20 andthe grounded radiator inlet 10.

It will, of course, be evident that the tube reasonably free to slide topermit opening of the valve in the event of undue pressure buildup inthe radiator, but a seal 60 is compressed between the cap 18 and plate20 to prevent escape of pressurized coolant and/or steam when the valveis thus opened, or opened manually by the pressure release lever 64.This lever 64 is bifurcated to straddle the tube 22 just underneath thelower shell 34 of the capsule and the lever is pivoted on an upwardlydimpled rim 66 on the cap 18.

A modified form of this invention is illustrated in FIG. 5. In thisembodiment the capsule 132 and casing 142 are identical to the capsule32 and casing 42 but the tube 22 is modified to constitute aself-tapping nipple 68 with a pilot 70 for easy'installment of thecapsule on the wall of a radiator.

In either form the capsule with its pressure-sensitive diaphragm andelectrical circuit make-and-break means is connected in series with awarning signal such as the lamp 72, a buzzer or the like usuallyremotely installed on the instrument panel of a vehicle, and a source ofenergy indicated at 74. It is preferred that the same be merely added tothe existing temperature-sensing circuit with the conventionaltemperature gauge 76 and with the two sensors in parallel as in thesimplified diagram of FIG. 6.

I claim as invention:

1. A loss of-pressure malfunction warning system for pressurized coolingsystems of motor vehicle engines and the like, comprising a capsulehaving means for connection and communication with a normallypressurized portion of the cooling system;

a diaphragm operatively mounted in said capsule to respond to changes inpressure in the cooling system;

an electrically operated remote warning signal means; and

a circuit make-and-break means in said capsule and connected in acircuit with said signal means and operated by said diaphragm saidmake-and-break means including electrical contacts normally springbiased to closed position and held open by said diaphragm while thecolling system maintains normal operating pressure.

2. Apparatus according to claim 1 wherein said cooling system includes aradiator and radiator cap and said capsule is mounted on said radiatorcap.

3. Apparatus according to claim 1 wherein said cooling system includes aradiator with a radiator tank and said means for connectionandcommunication comprises a self-tapping nipple whichiis mounted on theradiator tank.

4. Apparatus according to claim 1 wherein said cooling system includes aradiator and radiator cap and said means for connecting andcommunicating comprises a tube fixed to and extending through said capand communicating with one side of said diaphragm;

said make-and-break means comprising a plunger spring biased toward saiddiaphragm and carrying an electrical 22 must be contact to close saidcircuit when the diaphragm is not said spring and movement of said valveelement to relieve deflected by pressure in the cooling system. pressurein said cooling system. Apparatus according to clam 4 and mcludmg aValve 6. Apparatus according to claim 1 and including a temperament onsaid tube biased by a spring controlling the upper limit of pressure inthe cooling system, and a lever operatively 5 mounted on said cap formanual movement of said tube and capsule relative to the cap andconsequent compression of ture-sensing means operatively mounted in saidcooling system in parallel with said make-and-break means.

1. A loss-of-pressure malfunction warning system for pressurized coolingsystems of motor vehicle engines and the like, comprising: a capsulehaving means for connection and communication with a normallypressurized portion of the cooling system; a diaphragm operativelymounted in said capsule to respond to changes in pressure in the coolingsystem; an electrically operated remote warning signal means; and acircuit make-and-break means in said capsule and connected in a circuitwith said signal means and operated by said diaphragm saidmake-and-break means including electrical contacts normally springbiased to closed position and held open by said diaphragm while thecolling system maintains normal operating pressure.
 2. Apparatusaccording to claim 1 wherEin said cooling system includes a radiator andradiator cap and said capsule is mounted on said radiator cap. 3.Apparatus according to claim 1 wherein said cooling system includes aradiator with a radiator tank and said means for connection andcommunication comprises a self-tapping nipple which is mounted on theradiator tank.
 4. Apparatus according to claim 1 wherein said coolingsystem includes a radiator and radiator cap and said means forconnecting and communicating comprises a tube fixed to and extendingthrough said cap and communicating with one side of said diaphragm; saidmake-and-break means comprising a plunger spring biased toward saiddiaphragm and carrying an electrical contact to close said circuit whenthe diaphragm is not deflected by pressure in the cooling system. 5.Apparatus according to claim 4 and including a valve element on saidtube biased by a spring controlling the upper limit of pressure in thecooling system, and a lever operatively mounted on said cap for manualmovement of said tube and capsule relative to the cap and consequentcompression of said spring and movement of said valve element to relievepressure in said cooling system.
 6. Apparatus according to claim 1 andincluding a temperature-sensing means operatively mounted in saidcooling system in parallel with said make-and-break means.